The present teachings provide a blood purification apparatus in which inadvertent replacement of a container bag attached to a hanger portion can be avoided the blood purification apparatus including a holding device capable of holding a container bag that contains a liquid for blood purification treatment, such as dialysate, substitution fluid, or anticoagulant, the blood purification apparatus being capable of performing blood purification treatment using the liquid in the container bag, and the holding device including a hanger portion including an attachment portion to which the container bag can be attached, and movable between a use position and a replacement position, a measuring device capable of measuring the weight of the container bag held by the hanger portion, and a restricting device that restricts attachment and detachment of the container bag to and from the attachment portion when the hanger portion is in the use position.
